The present invention relates to a flow sensing venturi, and more particularly to a manifold which supports a multiple of sensors adjacent the flow sensing venturi.
A flow sensing venturi is typically provided in an aircraft environmental control systems (ECS). The venturi includes a multiple of electronic pressure sensors to measure airflow bled from a gas turbine engine. Each sensor communicates with the interior of the venturi through one or more sense lines which individually extend from the sensor and tap fluid flow through the venturi. Data from the sensor is then provided to an ECS digital controller to assure proper operation and control.
Each sensor is also thermally isolated from the venturi to enhance sensor reliability. Typically, a thermally isolated clamp locates each sensor a distance away from the venturi. The sense lines are relatively long to span the distance between the venturi and the thermally isolated sensors. An intricate arrangement of sensors, each having a multiple of sense lines is therefore mounted to the venturi.
It is desirable to provide for the removal and replacement of individual sensors, without removing the venturi from its installed position. Such maintenance may be further complicated when the venturi is installed within the confines of an aircraft as the mechanic must disconnect numerous pneumatic fittings and clamps within the tight space constraints of an aircraft environment. Moreover, following the replacement of an individual sensor, each individual connection of each sense line must be checked for leakage to assure proper function. This is again hindered by the tight space constraints.
Accordingly, it is desirable to provide a venturi having a line replaceable unit (LRU) sensor mounting arrangement that simplifies the in-situ removal and replacement of individual sensors within a space constrained installation.
The flow sensing venturi system according to the present invention includes a venturi body and a manifold mounted thereto. The manifold defines a multiple of sensor ports such that each sensor may be individually screwed into the manifold without connecting a multiple of sense lines.
The sensor is threaded into a threaded fitting located within the sensor port. The sensor threaded fitting surrounds a high pressure input port such that when the sensor is threaded into the sensor port, the high pressure input port is in communication with a high pressure passage formed in the manifold. A single high-pressure sense line communicates between the high-pressure passage and a high pressure region within the interior of the venturi body.
A low-pressure input port radially extends from the sensor adjacent the high pressure input port. A seal such as an O-ring is located about the outer diameter of the sensor opposite the high-pressure input port and past the low-pressure input port. The seal assures an airtight fit between the sensor and the sensor port such that the low pressure input port is sealed from ambient. That is, irrespective of the radial position of the low pressure input port within the low pressure radial areaxe2x80x94due to the sensor being threaded into placexe2x80x94the seal assures that the low pressure input port is isolated from ambient air pressure. A single low-pressure sense line communicates between the low pressure passage and a low pressure region within the interior of the venturi body.
Advantageously, the single high and low pressure sense lines need not be disconnected to replace an individual sensor. A single threaded connection provides an airtight connection for two independent sensor input ports. The present invention therefore provides a venturi having a line replaceable unit (LRU) sensor mounting arrangement that simplifies the in-situ removal and replacement of individual sensors within a space constrained installation.